Submitted to: Aquaculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/1/2004
Publication Date: 6/1/2004
Citation: Liu, K.K.M., F.T. Barrows, R.W. Hardy, F.M. Dong. 2004. Body Composition, growth performance and product quality of rainbow trout (Onchorynchus mykiss) fed diets containing poultry fat, soybean/corn lecithin, or menhaden oil. Aquaculture. 238:309-328 Interpretive Summary: Fish oil has been traditionally added to feeds as an energy source and as an essential fatty acid source. We evaluated poultry fat and soy/corn lecithin as a replacement for menhaden oil in rainbow trout diets. Weight gain or feed conversion was not affected by feeding the alternate oil sources. A yellowish color was imparted to the fillets of the fish fed the diets containing lecithin. This pigmentation originated in the corn portion of the lecithin product, and was more pronounced in the stored product. There was a trend to less stability of the fillets from fish fed the fish oil diets when stored for extended periods of time. In general, however, this study indicated a significant portion of the fish oil can be replaced with poultry oil or lecithin without affecting fish growth or fillet sensory characterisitics.
Technical Abstract: The suitability of soybean/corn lecithin and poultry fat as partial replacements for menhaden oil in feeds for post-juvenile rainbow trout (initial weight 46.0 g) was investigated. For 16 weeks, fish were fed experimental diets in which either 10% menhaden oil (FO), 10% poultry fat (PF), 10% lecithin (soybean/corn, L10), or 15% lecithin (soybean/corn, L15), plus 5% supplemental menhaden oil was added to fish meal-based diets. There were no significant differences in body weight gain among all treatments (328-347 g/fish), although fish feed the L15 diet consumed significantly more feed (299 glfish) than fish fed the PF diet (269 g/fish). Sonsory analysis indicated that raw L10 fillets stored for 4 and 12 weeks at -20 0C were significantly more yellow than raw FO fillets. Raw and cooked L15 fillets stored for 1 and 8 days at 5 0C, or for 17 days, 4 weeks, and 12 weeks at -20 0C had significantly higher colorimetric b* values (more yellow) than raw and cooked FO, PF, and L10 fillets. There was a trend for FO fillets to have higher TBARS values compared to fillets of the other treatments when stored under all time/temperature conditions tested. Although fillets of fish fed diets containing soybean/corn lecithin were more yellow in color, either lecithin (soybean/corn) or poultry fat was a nutritionally suitable substitute for most of the fish oil added to fish feeds.